Vacuum flow control for crankcase ventilation



Dec. 10, 1968 w. R. DRYSDALE -VACUUM FLOW CONTROL FOR CRANKCASE VENTILATION Filed Oct. 17, 1966 FIG.|

INVENTOR. WILLIAM R. DRYS DALE United States Patent M 3,415,233 VACUUM FLOW CONTROL FOR CRANKCASE .VENTILATION William R. Drysdale, 22240 Prospect St., Hayward, Calif. 94541 Filed Oct. 17, 1966, Ser. No. 587,218 3 Claims. (Cl. 123-419) ABSTRACT OF THE DISCLOSURE The vacuum flow control for crankcase ventilation makes use of a conduit leading from the engine crankcase and communicating with the carburetor chamber through an opening positioned at a point above the throttle valve and below the venturi for delivering crankcase fumes to the carburetor when the throttle valve is open. This opening is closed by the throttle valve when the latter is closed. However, a groove in the wall of the carburetor chamber communicates with the conduit, and the throttle valve has a recess in its periphery that registers with the groove when the valve is closed. The-groove and recess form a passageway when the throttle valve is closed and this passageway places the conduit from the crankcase in communication with the carburetor chamber on the downdraft side of the throttle valve so that fumes from the crankcase can be delivered to the carburetor below the throttle valve when the latter is closed and the engine is idling.

This invention relates to vacuum controlled ventilation of internal combustion engines as used on automotive vehicles.

It is known that vapors of oils, gasoline, acids, and water are found in the oil pan and lower crankcase of internal combustion engines where they become mixed with the oil and render it less elfective.

To prevent this result, it is known in the art to apply a tube or conduit to the upper part of the crankcase and connect this tube or conduit to the intake manifold of the engine so the suction of the intake manifold will draw unburned vapors from the crankcase through the tube or conduit and deliver them to the combustion chamber where they are burned and expelled in due process past the exhaust valve and out the exhaust pipe.

The flow of gases from the crankcase through the tube or conduit must be controlled to provide for uniform flow as the speed of the engine changes.

To control the flow of gases through the tube or conduit from the crankcase a tube or conduit is placed into communication with the chamber of the carburetor just above the carburetor throttle valve and below the venturi and fuel jets in the carburetor.

A second passageway from the tube or conduit above the throttle valve to convey the fumes below the throttle valve, when closed, an open groove is cut in the inside wall of the carburetor passageway to extend below the throttle valve when the throttle valve is closed, there is a groove cut in the disc of the throttle valve to correspond or match with the open groove cut in the carburetor passageway to form an orifice when the throttle valve is closed to control the flow of gases or fumes from the crankcase to intake manifold when the engine idles.

When the throttle valve is closed a small amount of gases and fumes from the crankcase flow through the upper tube or conduit to the carburetor above the throttle valve, then through the grooved passageway or conduit to the limit of the appropriate orifice in the grooved conduit in the wall of the carburetor wall and the grooved cut in disc of throttle valve when closed to form the orifice, for maximum flow.

3,415,233 Patented Dec. 10, 1968 The flow of the gases through the tube or conduit from the crankcase to the carburetor is controlled by the opening or closing of the throttle valve in the carburetor, to increase or decrease the vacuum in the crankcase as the blowby charges into the crankcase.

The orifice in the tube or conduit above the throttle valve and the orifice formed by the grove in carburetor wall passageway, and the groove cut from the throttle valve disc, when closed, control the maximum flow of gases from the crankcase to the carburetor and manifold for the required mixture of gases to the combustion chamber of the engine.

It is the object of the present invention to provide a vacuum control means or members which can be controlled by the throttle valve in the carburetor, using only one tube or conduit from the crankcase, and self cleaning orifices that can be manufactured at very reasonable cost having no valves or moving parts.

Another object of the invention is to provide a connection into the carburetor, below the gasoline jets and venturi above and below the throttle valve in the carburetor, to prevent fouling of the gasoline jets and upper parts of the carburetor, by gases, oil fumes, and carbon from the crankcase.

Another object of the invention is to provide self cleaning of the open groove or passageway for the idle orifice by the flow of raw gasoline over the orifices when the engine is started and the choke valve in the carburetor is closed to enrich the mixture of gases.

The vacuum in the tube or conduit to the crankcase will increase as the throttle valve in the carburetor is opened and the blowby increases in the crankcase.

These, together with other objects and advantages, will become apparent from details of construction and operation as more fully described and claimed hereinafter, reference being had to the accompanying description and drawings, wherein like numerals refer to like parts throughout.

FIGURE 1 is an end view of an internal combustion engine with the invention applied.

FIGURE 2 is an enlarged fragmentary view partly in section of the invention.

FIGURE 3 is an enlarged horizontal section showing the throttle valve disc in closed position. The disc has a recess in its periphery that registers with a groove in the adjacent wall surface to form a passage that places the tube from the crankcase in communication with the carburetor chamber at a point below the disc when the throttle valve is closed.

FIGURE 4 is a horizontal section through the carburetor chamber and the throttle valve disc is omitted in order to show the groove in the carburetor chamber wall.

FIGURE 5 is a horizontal section through only the throttle valve disc and illustrates the recess in its periphery that registers with the groove when the disc is in closed position.

A crankcase 15 is provided with the usual filler pipe vent opening 8 for the air to enter. The air is drawn by suction at the manifold through the crankcase 15, picks up blowby gases and oil fumes, or as drawn through the valve cover 9 or other compartment of crankcase, and then passes into tube or conduit 10 through orifice 13 into carburetor chamber 6 between venturi 5 and throttle valve 7 when the valve is open so as not to enrich the mixture and flow of fumes as controlled by the throttle valve in the carburetor. The orifice 13 is closed by the throttle valve 7 when the latter is in closed position. When throttle valve in carburetor is closed, the air and gases drawn in through tube or conduit 10 pass through groove or passageway 11 cut in carburetor wall and valve orifice 12 that registers with the groove 11 when the throttle valve is closed for idling of the engine only.

In FIGURE 2 there is an enlarged showing of conduit leading from the crankcase to the carburetor chamber 6 above the throttle valve 7 and to the groove 11 or open conduit in wall of carburetor extending below the throttle valve 7. The recess or groove 12 that is cut out of the throttle valve 7 will match the groove or open conduit 11 in the carburetor pasageway, when the throttle valve is closed and will control the flow of gases through conduit 10 and orifices 11 and 12 so that the vacuum in the crankcase 15 will be maintained at or near even flow through the crankcase 15 and other compartments, and so that there will be no discharge of fumes from the oil filler pipe and cap 8.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

Having thus completely and fully described the invention, what is now claimed as new is as follows:

1. A vacuum flow control device for an internal combustion engine having a crankcase and an induction system including a carburetor providing a chamber enclosing a venturi and an intake manifold having a throttle valve therein, comprising:

(a) a conduit providing free passageway connecting said crankcase with said induction system between said throttle valve and the downstream side of said venturi, said free passageway being gauged to equalize the pressure in said induction system between the throttle valve and said venturi with the pressure in the crankcase when the engine is running with the throttle valve open;

(b) said carburetor chamber wall having a groove therein communicating with said conduit and extending into the downstream side of the carburetor intake manifold below the throttle valve when the latter is closed, the throttle valve having a recess in its periphery that registers with the groove in the carburetor chamber wall to form a second passageway that communicates with the downstream side of the throttle valve when the latter is closed, the size of the second passageway formed by the groove and the recess being gauged on the downstream side of the throttle valve with the pressure in the crankcase when the throttle is closed and the engine is idling, the equalizing of pressure being effected by variations in pressure in the induction system.

2. The combination as set forth in claim 1, and in which (a) the passageway formed by the groove in the carburetor intake manifold wall and the recess in the periphery of the throttle valve when the latter is closed is open to the portion of the carburetor intake manifold wall disposed directly above the throttle valve and will be self-cleaned by the flow of extra gasoline that flows through the main passageway of the carburetor when the engine is started and the choke valve in the carburetor is closed.

3. A vacuum flow control device for crankcase ventilation for an internal combustion engine having a crankcase, an oil filler pipe, and a carburetor with a venturi and a throttle valve comprising:

(a) a conduit providing a free pasageway between the crankcase and the carburetor above the throttle valve and below the venturi;

(b) a second passage communicating with the first passageway and being formed by a groove in the carburetor wall and a recess in the periphery of the throttle valve that registers with the groove when the latter is closed, the second passage leading to the downstream side of the throttle valve and providing a free passageway from the crankcase to a point below the throttle valve when the throttle valve is closed and closes communication between said conduit and the carburetor chamber portion disposed above said valve; the second passage being gauged in correlation to the volume of fumes generated when the throttle valve is closed and the engine is idling; the second passageway being self-cleaning by the flow of extra gasoline that flows through the carburetor when the engine is started and the choke valve is closed in the carburetor.

References Cited UNITED STATES PATENTS 2,516,547 7/1950 Carlson et al. l23-ll9 3,116,727 1/1964 Dietrich 1231l9 3,241,535 3/1966 Drysdale l23119 AL LAWRENCE SMITH, Primary Examiner. 

